From: Timo Schlüßler <schluessler@xxxxxxxxx>
The mcp251x variants feature 3 general purpose digital inputs and 2
outputs. With this patch they are accessible through the gpio framework.
Signed-off-by: Timo Schlüßler <schluessler@xxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
drivers/net/can/spi/mcp251x.c | 251 ++++++++++++++++++++++++++++++++++
1 file changed, 251 insertions(+)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index a0695d6b5df2..b73a289c7d8b 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -41,6 +41,7 @@
*/
#include <linux/can/core.h>
+#include <linux/bitfield.h>
#include <linux/can/dev.h>
#include <linux/can/led.h>
#include <linux/can/platform/mcp251x.h>
@@ -62,6 +63,8 @@
#include <linux/spi/spi.h>
#include <linux/uaccess.h>
#include <linux/regulator/consumer.h>
+#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
/* SPI interface instruction set */
#define INSTRUCTION_WRITE 0x02
@@ -77,6 +80,30 @@
/* MPC251x registers */
+#define BFPCTRL 0x0c
+# define BFPCTRL_B0BFM BIT(0)
+# define BFPCTRL_B1BFM BIT(1)
+# define BFPCTRL_BFM(n) (BFPCTRL_B0BFM << (n))
+# define BFPCTRL_BFM_MASK GENMASK(1, 0)
+# define BFPCTRL_B0BFE BIT(2)
+# define BFPCTRL_B1BFE BIT(3)
+# define BFPCTRL_BFE(n) (BFPCTRL_B0BFE << (n))
+# define BFPCTRL_BFE_MASK GENMASK(3, 2)
+# define BFPCTRL_B0BFS BIT(4)
+# define BFPCTRL_B1BFS BIT(5)
+# define BFPCTRL_BFS(n) (BFPCTRL_B0BFS << (n))
+# define BFPCTRL_BFS_MASK GENMASK(5, 4)
+#define TXRTSCTRL 0x0d
+# define TXRTSCTRL_B0RTSM BIT(0)
+# define TXRTSCTRL_B1RTSM BIT(1)
+# define TXRTSCTRL_B2RTSM BIT(2)
+# define TXRTSCTRL_RTSM(n) (TXRTSCTRL_B0RTSM << (n))
+# define TXRTSCTRL_RTSM_MASK GENMASK(2, 0)
+# define TXRTSCTRL_B0RTS BIT(3)
+# define TXRTSCTRL_B1RTS BIT(4)
+# define TXRTSCTRL_B2RTS BIT(5)
+# define TXRTSCTRL_RTS(n) (TXRTSCTRL_B0RTS << (n))
+# define TXRTSCTRL_RTS_MASK GENMASK(5, 3)
#define CANSTAT 0x0e
#define CANCTRL 0x0f
# define CANCTRL_REQOP_MASK 0xe0
@@ -257,6 +284,10 @@ struct mcp251x_priv {
struct regulator *power;
struct regulator *transceiver;
struct clk *clk;
+#ifdef CONFIG_GPIOLIB
+ struct gpio_chip gpio;
+ u8 reg_bfpctrl;
+#endif
};
#define MCP251X_IS(_model) \
@@ -387,6 +418,216 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
mcp251x_spi_trans(spi, 4);
}
+#ifdef CONFIG_GPIOLIB
+enum {
+ MCP251X_GPIO_TX0RTS = 0, /* inputs */
+ MCP251X_GPIO_TX1RTS,
+ MCP251X_GPIO_TX2RTS,
+ MCP251X_GPIO_RX0BF, /* outputs */
+ MCP251X_GPIO_RX1BF,
+};
+
+#define MCP251X_GPIO_INPUT_MASK \
+ GENMASK(MCP251X_GPIO_TX2RTS, MCP251X_GPIO_TX0RTS)
+#define MCP251X_GPIO_OUTPUT_MASK \
+ GENMASK(MCP251X_GPIO_RX1BF, MCP251X_GPIO_RX0BF)
+
+static const char * const mcp251x_gpio_names[] = {
+ [MCP251X_GPIO_TX0RTS] = "TX0RTS", /* inputs */
+ [MCP251X_GPIO_TX1RTS] = "TX1RTS",
+ [MCP251X_GPIO_TX2RTS] = "TX2RTS",
+ [MCP251X_GPIO_RX0BF] = "RX0BF", /* outputs */
+ [MCP251X_GPIO_RX1BF] = "RX1BF",
+};
+
+static inline bool mcp251x_gpio_is_input(unsigned int offset)
+{
+ return offset <= MCP251X_GPIO_TX2RTS;
+}
+
+static int mcp251x_gpio_request(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 val;
+
+ /* nothing to be done for inputs */
+ if (mcp251x_gpio_is_input(offset))
+ return 0;
+
+ val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, val, val);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl |= val;
+
+ return 0;
+}
+
+static void mcp251x_gpio_free(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 val;
+
+ /* nothing to be done for inputs */
+ if (mcp251x_gpio_is_input(offset))
+ return;
+
+ val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, val, 0);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl &= ~val;
+}
+
+static int mcp251x_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ if (mcp251x_gpio_is_input(offset))
+ return GPIOF_DIR_IN;
+
+ return GPIOF_DIR_OUT;
+}
+
+static int mcp251x_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 reg, mask, val;
+
+ if (mcp251x_gpio_is_input(offset)) {
+ reg = TXRTSCTRL;
+ mask = TXRTSCTRL_RTS(offset);
+ } else {
+ reg = BFPCTRL;
+ mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);
+ }
+
+ mutex_lock(&priv->mcp_lock);
+ val = mcp251x_read_reg(priv->spi, reg);
+ mutex_unlock(&priv->mcp_lock);
+
+ return !!(val & mask);
+}
+
+static int mcp251x_gpio_get_multiple(struct gpio_chip *chip,
+ unsigned long *maskp, unsigned long *bitsp)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ unsigned long bits = 0;
+ u8 val;
+
+ mutex_lock(&priv->mcp_lock);
+ if (maskp[0] & MCP251X_GPIO_INPUT_MASK) {
+ val = mcp251x_read_reg(priv->spi, TXRTSCTRL);
+ val = FIELD_GET(TXRTSCTRL_RTS_MASK, val);
+ bits |= FIELD_PREP(MCP251X_GPIO_INPUT_MASK, val);
+ }
+ if (maskp[0] & MCP251X_GPIO_OUTPUT_MASK) {
+ val = mcp251x_read_reg(priv->spi, BFPCTRL);
+ val = FIELD_GET(BFPCTRL_BFS_MASK, val);
+ bits |= FIELD_PREP(MCP251X_GPIO_OUTPUT_MASK, val);
+ }
+ mutex_unlock(&priv->mcp_lock);
+
+ bitsp[0] = bits;
+ return 0;
+}
+
+static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 mask, val;
+
+ mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);
+ val = value ? mask : 0;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl &= ~mask;
+ priv->reg_bfpctrl |= val;
+}
+
+static void
+mcp251x_gpio_set_multiple(struct gpio_chip *chip,
+ unsigned long *maskp, unsigned long *bitsp)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 mask, val;
+
+ mask = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, maskp[0]);
+ mask = FIELD_PREP(BFPCTRL_BFS_MASK, mask);
+
+ val = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, bitsp[0]);
+ val = FIELD_PREP(BFPCTRL_BFS_MASK, val);
+
+ if (!mask)
+ return;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl &= ~mask;
+ priv->reg_bfpctrl |= val;
+}
+
+static void mcp251x_gpio_restore(struct spi_device *spi)
+{
+ struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+ mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl);
+}
+
+static int mcp251x_gpio_setup(struct mcp251x_priv *priv)
+{
+ struct gpio_chip *gpio = &priv->gpio;
+
+ /* gpiochip handles TX[0..2]RTS and RX[0..1]BF */
+ gpio->label = priv->spi->modalias;
+ gpio->parent = &priv->spi->dev;
+ gpio->owner = THIS_MODULE;
+ gpio->request = mcp251x_gpio_request;
+ gpio->free = mcp251x_gpio_free;
+ gpio->get_direction = mcp251x_gpio_get_direction;
+ gpio->get = mcp251x_gpio_get;
+ gpio->get_multiple = mcp251x_gpio_get_multiple;
+ gpio->set = mcp251x_gpio_set;
+ gpio->set_multiple = mcp251x_gpio_set_multiple;
+ gpio->base = -1;
+ gpio->ngpio = ARRAY_SIZE(mcp251x_gpio_names);
+ gpio->names = mcp251x_gpio_names;
+ gpio->can_sleep = true;
+
+ return gpiochip_add_data(gpio, priv);
+}
+
+static void mcp251x_gpio_remove(struct mcp251x_priv *priv)
+{
+ gpiochip_remove(&priv->gpio);
+}
+#else
+static inline void mcp251x_gpio_restore(struct spi_device *spi)
+{
+}
+
+static inline int mcp251x_gpio_setup(struct mcp251x_priv *priv)
+{
+ return 0;
+}
+
+static inline void mcp251x_gpio_remove(struct mcp251x_priv *priv)
+{
+}
+#endif
+
static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
int len, int tx_buf_idx)
{
@@ -795,6 +1036,7 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
if (priv->after_suspend & AFTER_SUSPEND_POWER) {
mcp251x_hw_reset(spi);
mcp251x_setup(net, spi);
+ mcp251x_gpio_restore(spi);
} else {
mcp251x_hw_wake(spi);
}
@@ -1195,9 +1437,16 @@ static int mcp251x_can_probe(struct spi_device *spi)
devm_can_led_init(net);
+ ret = mcp251x_gpio_setup(priv);
+ if (ret)
+ goto error_gpio;
+
netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
return 0;
+error_gpio:
+ mcp251x_gpio_remove(priv);
+
error_probe:
mcp251x_power_enable(priv->power, 0);
@@ -1219,6 +1468,8 @@ static int mcp251x_can_remove(struct spi_device *spi)
unregister_candev(net);
+ mcp251x_gpio_remove(priv);
+
mcp251x_power_enable(priv->power, 0);
if (!IS_ERR(priv->clk))
--
2.24.0.rc1
